Stretch laminates are used, for example, in the construction of hygiene products. Hygiene products may include, but are not limited to: diapers, absorbent articles, training pants, youth pants, adult incontinence products, and the like. For example, see U.S. Pat. No. 7,794,819 and the references cited therein, each of which is incorporated herein, in their entirety, by reference.
In general, stretch laminates may be structures having two or three layers laminated together, so that the laminated structure is elastic (e.g., stretchable and recoverable) in at least one direction. The two layer laminate typically includes a non-woven fabric (or film) laminated to an elastic film, and the three layer laminate typically includes two non-woven fabrics (or films) sandwiching the elastic film.
Stretch laminates may be used as various components of the hygiene product. In one example, the stretch laminate is used to form the ‘side panel ears’ or ‘tabs’ of the hygiene product. The side panel ears and tabs are used to secure the hygiene product around the waist of the wearer. Typically, the side panel ears or tabs are affixed to the lateral rear portions of the hygiene products, and may be releasably fastened to the front portion of the hygiene product, when that product is in use on the wearer.
These side panel ears or tabs are typically elastic. The elasticity of the side panel ears or tabs helps to insure a secure and snug fit of the hygiene product to the wearer. In use, for example, the side panel ears or tabs may be stretched from the rear portion of the product and around the wearer, and are releasably fastened to the front of the product, and the side panel ears or tabs retract to provide the secure and snug fit to the wearer.
These side panel ears and tabs may be breathable or non-breathable. Non-breathable side panel ears or tabs may be uncomfortable for wearers and may be prone to cause infections due to the high moisture content between the skin and non-breathable side panel ear. These products mimic traditional underwear design and could potentially be worn for longer periods of time as older children/adults have more control over their bladder. This longer wear time may also contribute to skin irritation/degradation due to moisture between the laminate and user. In particular, in countries where the atmosphere has a high temperature and/or high rate of humidity. Breathable side panel ears or tabs may be perforated. The perforations allow the moisture to escape and the skin to “breathe”. But, the problem with perforating a film is the perforations make the ear inherently weak by providing a route for a tear propagation as the ear is stretched. The stretching could be made when the product is manufactured on a manufacturing line, and/or when activated, and/or when the product is rolled and/or unrolled in order to manufacture the hygiene article, and/or when the hygiene article is fit on the wearer or during use.
Accordingly, there is a need to make a breathable (e.g., perforated) stretch laminate that is resistant to tearing or tear propagation when stretched.
U.S. Pat. No. 5,336,554 discloses a stretchable tear resistant porous elastomeric film in which the perforation are made by laser beams. USD637008 shows a stretch laminate incorporating a design. US2012/0244412 discloses a perforated film. U.S. Pat. No. 8,795,809 discloses a tear resistant elastic film made with a SEEPS elastomeric block copolymer. IPS Hole Pattern 14.2 from International Perforating Services, Inc of Statesville, N.C. is a perforation pattern which is decorative and used for rigid supports, has good air flow and good acoustical properties (but makes no reference to resistance to tearing or tear propagation, in particular no reference about a stretch laminate). Each of the foregoing references are incorporated herein, in their entirety, by reference.